1. Field of the Invention
This invention relates to shafts and handles of a variety of sporting goods and light weight tubular structural components, and most particularly it relates to metallic tubular shafts as used on golf clubs, ski poles and fishing rods.
Shafts of this type are commonly constructed of steel and aluminum and composites and are objectionable for several reasons, including weight, rigidity, or they do not have the desired flexibility and torque resistance which is essential in shafts of this type. There have been many structural improvements in shaft construction, including reinforcing the tubular shafts with metallic compressible tubular materials having a plurality of re-entrant portions extending longitudinally and separated by longitudinally extending ribs and by filling the hollow shaft with plastic material or sponge rubber. The instant invention offers a method for reinforcing shafts by furnace or vacuum brazing a helical wire portion inside the shaft.
2. Description of the Related Art
A pertinent prior art reference is U.S. Pat. No. 1,994,069 issued in 1935 to C. T. Fletcher, which describes a tubular metallic shaft closely simulating the wooden shaft used on a golf club, and interiorly reinforcing it with a convoluted material having re-entrant portions extending longitudinally thereof and separated by longitudinal ribs. U.S. Pat. No. 1,950,342 issued in 1934 to
Irving Meshel which describes a hollow tubular metallic "steel" shaft with a core of sponge rubber. U.S. Pat. No. 3,762,707 issued in 1973 to Salvatore Santorelli, which describes a golf club comprising a hollow shaft with a grip at one end and a golf head attached to the other end. The shaft is made of a material to impart a predetermined flexibility to the shaft. The shaft is partially filled from the attachment and up to a predetermined distance within the shaft, with a manually flexible plastic material.